Encapsulated seat stabilizing mechanism



March 27, 1962 A. M. STOTT 3,027,124

ENCAPSULATED SEAT STABILIZING MECHANISM Filed Feb. 15, 1961 2 Sheets-Sheet 1 IGw INVENTOR. ALBE RT M. STOTT ATTORNEYS March 27, 1962 A. M. STOTT 3,027,

ENCAPSULATED SEAT STABILIZING MECHANISM Filed Feb. 15, 1961 2 Sheets-Sheet 2 INVENTOR. ALBERT M. STOTT Y 5 4 211 a; QW W ATToRNEYs:

" d States Patented Mar. 2?, i962 ice 3,027,124 ENCAPSULATED SEAT STABILIZING MECHANISM Albert M. Stott, AidamClirton Heights, Pa., assignor to the United States of America as represented by the Secretary oi the Army Filed Feb. 13, 1961, Ser. No. 89,079 1 Claim. (Cl. 244-422) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a mechanism for stabilizing an encapsulated aircrew seat upon its ejection from a disabled aircraft. Its principal object is the provision of a seat stabilizing mechanism which is operable by a gas pressure and functions to position and extend a pair of stabilizing fins in timed sequence.

It is known that stabilization of an encapsulated seat can be accomplished by twin stabilization booms which are normally stowed in a retracted position at the rear of the seat. In an emergency, the booms are repositioned angularly toward the rear, still firmly attached to the seat. In the final boom position, the fins are unfolded so that they present a larger area to the airstream for aerodynamic stabilization.

The present invention provides a mechanism which is operated by a gas pressure to first position and then unfold the stabilization fins. As will appear, this mechanism includes a boom in the form of a pair of telescopic tubes, relative movement between these tubes being utilized to effect the various motions required to stabilize the seat.

The invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope is indicated by the appended claims.

Referring to the drawings:

FIG. 1 is a partial sectional view of the mechanism,

FIGS. 2 and 2A illustrate the mechanism as it is normally stowed behind the seat, and

FIG. 3 shows the mechanism as it is positioned to stabilize the seat.

As indicated by FIG. 1, the mechanism includes an inner tube 1 which is attached through a firing head 4 to a predetermined point on the back of the seat 2 by a pivot 3. The firing head 4 includes a conventional gas unlock system coupled to a firing pin. As is well known, this firing pin operates to fire an explosive cartridge whereby a gas pressure is generated within the tube 1. The various details of this firing head are too well known to those skilled in the art to require detailed description. It may be similar to that shown in FIG. 1 of US. Patent 2,880,572.

Surrounding and movable with respect to the inner tube 1 is an outer tube 5 which has an end cap 6 with a central opening 7.

A link 8 is attached at one end to the outer tube 5 by a pivot 9 and at the other end to the back of the seat by a pivot 10. It is to be noted that the pivots 3 and 10 are spaced apart on the back of the seat so that the telescopic boom 1-5 is rotated about the pivot 3 when the outer tube 5 is moved away from the firing head 4 which is fixed to the end of the inner tube 1. While the link 8 is shown as including a cylinder 11 and a piston 12 which works against a buffer liquid, it may be replaced by a link of fixed length.

Movable within the inner tube 1 by the gas pressure generated by the firing head 4 is a piston I3 which is hollow, has an inlet 14 near its inner end and is extensible beyond the end 15 of the tube 1. A fin positioning piston 16 is movable within the piston 13 by gas ad mitted through the inlet 14 when this inlet clears the end 15 of the inner tube 1. The piston 16 has a longitudinal guide slot which cooperates with guide pin 16a threaded into the cap 6. A shear pin 22 couples the piston 16 to the cap 6.

Attached to the outer tube 5 by pivots 17 are a pair of fins 18 and 19 which are connected through a link 20 and a pivot 21 to the fin positioning piston 16. FIG. 2 shows the fins in their retracted position and FIG. 3 shows them in their extended position.

In the operation of the mechanism, a gas pressure applied to the hollow piston 13 pushes this piston against the end cap 6, moving the outer tube 5 with respect to the inner tube 1 and swinging the telescopic boom 1-5 about the pivot 3 with the end cap moving away from the back of the seat. Near the end of this movement, the inlet 14 clears the end 15 of the inner tube 1 so that a gas pressure is applied to the fin positioning piston 16. As a result, this piston is moved from its retracted position (FIGS. 1 and 2) to its extended position (FIG. 3). This movement of the piston 16 operates through links 20 to move the fins 18 and 19 from their retracted position (FIG. 2) to their extended position. (FIG. 3).

I claim:

The combination of an aircrew encapsulated seat, and a mechanism for stabilizing said seat upon its ejection from a disabled aircraft, said mechanism including an inner tube pivoted at one end to a predetermined point on the back of said seat, an outer tube, an end cap having a central opening and fixed to one end of said outer tube, a link having one of its ends: pivoted to the other end of said outer tube and its other end pivoted to the back of said seat at a point spaced from said predetermined point, means providing a gas pressure within said inner tube, a hollow piston having an inlet near its inner end and movable by said gas pressure against said end cap for moving said outer tube with respect to said inner tube, said piston being extensible beyond the end of said inner tube, a fin positioning piston movable in said hollow piston and through said central opening by a gas pressure applied through said inlet when said inlet clears the end of said inner tube, a pair of seat stabilizing fins pivoted to said outer tube, and a linkage between said fins and the outer end of said fin stabilizing piston whereby said fins are retracted when said fin positioning piston is retracted and are extended when said fin positioning piston is extended.

References Cited in the file of this patent UNITED STATES PATENTS 2,702,680 Heinemann et a1. Feb. 22, 1955 2,829,850 Culver Apr. 8, 1958 2,931,598 Sanctuary Apr. 5, 1960 2,947,503 Holcomb Aug. 2, 1960 2,959,382 Turner Nov. 8, 1960 OTHER REFERENCES Aviation Week Magazine, Aug. 26, 1957. (Pages 30 and 31.) 

